Severe lower limb defects in exstrophy of the cloaca.

We present here a patient with exstrophy of the cloaca associated with severe lower limb defects. The limb malformations include, on the right, a split foot with distal separation of the tibia and fibula, and on the left, attachment of the lower half of the left leg with a two-toed foot at nearly a right angle to the mid left thigh. A review of the literature indicates that 17-26% of patients with cloacal exstrophy also have lower limb defects. We hypothesize that cloacal exstrophy and associated lower limb defects have a related pathogenesis and that both are related to deficiencies of caudal mesoderm or mesodermal differentiation signals. More cases of exstrophy of the cloaca with limb defects need to be reported to better characterize the limb anomalies and to more precisely determine their frequency. Copyright 2004 Wiley-Liss, Inc.